This book contains the proceedings of the 39th University of Nottingham Feed Conference (includes CD-ROM). Initially, the proceedings deal with various aspects of nonruminant nutrition; an update on energy evaluation systems for pigs is followed by new developments in the interaction between the immune response and nutritional factors; this theme was extended by considering tryptophan specifically in piglet diets from both a requirement and health status perspective. Subsequently, there is a paper on nutrition of the newly hatched chick and finally, one on aquaculture: current issues for feed manufacturers.